Pipe joint assemblies using plastic sleeves are known from the prior art. Plastic sleeves of such assemblies are used only for mechanical fixing of the pipe and joint elements relative to each other, while impermeability is ensured by using additional sealing element of rubber or some other elastic material. The drawback of such joints is the usage of additional sealing element, which because of the factors coming from the transported media, such as temperature or chemical aggressiveness, could lose its elastic properties or could be destroyed, resulting in damaging of the seal of the joint (Annex to the <<Polymer pipes>> journal, Polymer pipes 2005>> handbook, Volume 1, pages 207-228.).
The closest analogue is pipe joint assembly, comprising fitting situated inside of the pipe, with coupling on the outside surface of the pipe, covering the fitting (Patent RF 64318, MPK F 16L13/007, published 27 Jun. 2007). In order to provide a sealed connection of the pipes, the joint is being compressed over the surface of the fitting, resulting in no necessity to use additional sealing element.
The drawback of the closest analogue is a necessity to prepare ends of the pipes: they have to be widen, in other words—bell-mouth, which leads to increased diameter of the pipe end and consequently to a changed geometry of the pipe end, including its reinforcement system, which subsequentially leads to destruction or weakening of the pipe. “Mouthing” of multilayered pipes may lead to cracking of one or several of their layers resulting in low functionality of these layers, leading to reduced reliability of the joint assembly. This makes the use of polymer pipe joint assemblies more complicated.